Liquid fuel burner



Dea., 49 @945. R. w. DE LANCEY 293%059 LIQUID FUEL BURNER' Filed Jan. l, 1943 2 Sheets-Sheet l and Meier/'ng INVENTOR RALPH W .DELNCEV ATTORNEY Een.:o 44, 1945 I LIQUID FUEL BURNER Filed Jan. l, 1945 TlrI'f- R. w. DE LANCEY v 2 Sheets-Shet 2 n RALPH W ELANCEV Enrv nNvN-rom Patented Dec. 4, 1945 l (miran` STATES PA'i'sNr ortica n Lrdumzrslmm Ralph W. De Lancey, Meriden, Conn., assigner to The Miller Company, Meriden, Conn., a corporation of Connecticut Application January 1, 194s, serial No. 410,960 13 claims. '(cl. 15s-,91)

The present invention relates=to liquid fuel burners, and is more particularly directed toward pot type burners adapted to be supplied with fuel at a high rate for high fire and at a low rate for pilot operation and employing a blower to supply air for combustion.

According to the more usual designs ofva'porizing pot type burners of the type referred to the blast of air blown into the vaporizing pot and combustion chamber is determined by the air pressure employed and the size and distribution of the air passages through which the air must travel to get to the various parts of the burner, these air'controlling passages being of unvarying dimension' so that the proportioning of the air stream is the same whenever the blower is lin operation. VAs it is necessary to provide ample air for complete combustion at high fire, and the burner operates a great deal of the time at low lire, a very great excess of air is passing through the burner at that time.

The present invention contemplates improvements in oil burners of the type referred to according to which a larger proportion of the air is directed down into the vaporizer during low fire and pilot operation than during high fire. This makes it possible to provide a greater proportional supply of oxygen to the inner part of the vaporizer during low ilre or pilot operation than during high re, and to supply a greater portion of air to the remainder of the combustion space in the burner during high fire operation when such added air is required for thecombustion of theofuel.

The present invention alsoV contemplates that the redistribution of the -air ilofw will be accomplished by means automatically set into operation at the same time as the metering valve which controls the rate of flow of fuel. Preferably the means for redistributing the air ilow is operated by a. thermostat lhaving a. normal or cold position corresponding with the position of the parts'for low fire or pilot operationy and another or heated position corresponding with the posi-- tion to be assumed during high nre operation, this thermostat being preferably actuated by a heater in parallel with the heater employed in the thermostatically operated metering valve. The operation of these thermostatically operated devices is coordinated by designing them to have the proper time constants.

. The accompanying drawings shorw,` for purposes of illustrating the present invention three of the many embodiments in which the invention may take form, it being understood that the drawings are illustrative of the invention rather than limiting the same. Y

In these drawings:

Figure l is a side elevational view of a liquid fuel burner with controls and blower, parts being in section; l

Figure 2 is an enlarged sectional view of the burner; Figure 3 is a view similar to Figure 2 showing a modified form of construction; and v Figures 4 and 5 illustrate a further m'odication.

In the drawings the combined constant level and thermostatically operated metering valve of conventional design is diagrammatically indicated at ill, and the blower for supplying air at ll. 'The air is blown through a conduit l2 of the l burner proper, while the oil flows `from the lio metering valve through pipe I3 to the vaporizer ll of the burner. This vaporizer is annular and has a sloping lower wall i5 to form a pool of oil baille 2i spaced above the same and adapted to Y direct airdown toward the openings i9.- This bale has a central opening 2i' through which air escapes to pass out under the flame spreader.

A perforated sleeve '22 extends upwardly from the outside of the vaporizer. The vaporizer and sleeve are supportedfrom an upper ring 22' and are received in a cylindrical housing 23 which rests on'top of the conduit l2 and carries the ring 22.

.A vertical shaft 2l extends from the conduit if up through the inside of the vaporizer and the central air distributor and is guided for vertical movement forrany suitable means. The upper l end of this shaft 24 has a conical damper or shutter member 25 adapted to cooperate with the opening 2l' in the baille 2|. The vaporizer supports an annular diaphragm or baille 26 which reaches down towardthe bottom of the housing 23, and, as discussed in my application Serial No. 470,961, iiled concurrently herewith, may be designed to reduce the pressure of the air supplied to the perforated sleeve to an amount substantially below the pressure of the air supplied to the central air distributor and out under the baille 2| and down through openings i! into the vaporizer, except that which is allowed to escape about the shutter member 21. When the shaft 2l is moved up to the dotted line position air can escape out under the diaphragm 20, and pass 'up outside the perforated sleeve 22, and then blow in across the vaporizer. also some of the air coming up through the central air distributor can escape out under the flame spreader. When the parts are in the latter mentioned position air is provided for combustion of the fuel fed for high fire.

In order to automatically effect the movement ofthe shaft 24 at the proper time it is under the control of a suitable mechanism such as a lever pivoted at 3| and movable from the full line to the dotted line position by a bimetallic thermostat I2 which is under the control of a heater As shown in' Figure 1 of the drawings the heater 33 is in parallel with the heater 34 for the bilmetallic operating member 35 of the metering valve. I'his circuit is usually under the control of a room thermostat. such as indica-ted at $8. but of course mav be under the control of a manual switch. The metering valve will usually supply the proper amount of fuel for pilot operation and both therrnostats 32 and Il will be cool and all the. air will be directed down through the openings i9. 0n demand for heat the thermostat 3l will open the metering valve and in proper timed relation depending upon the hea-ting characteristics for the two thermostats the thermostat 32 will flex downwardlv and change the air passages so that the. air is directed in the proper manner for burning the large amount of fuel.

In the arrangement shown in Figure 1 one can omit the lower shutter 21 so that at all times air :illoevs in through the perforated sleeve, if de- In the construction shown in Figure 3 the vaporizer i4. central air distributor Il. flame spreader I1 and the outer parts of the housing (not shown-nv are the same as in Figure 2. Instead of providing the bottom of the housing with a large opening. as indicated in Figure 2 here the bot` tom lil of the housing has a smaller opening I through which all the air from tbe conduit I2 passes to the burner structure. A vertical rod B2 similar to the rod 2l extends up through the center of the burner. its lower end resting on the thermostatic lever as previouslv described. The shaft nr rod 52 carries an upper cone I3 and a cylinder 5I which is adapted to engage with the housing bottom when the thermostat is cold. The cylinder Bl is received within a sleeve 55 which extends down from inside the vaporizer preferablv of small enough diameter so that it can be withdrawn upwardly through the opening in the vaporizer when the central. air distributorl is removed. The lower edge lil of the cylinder Il is spaced above the bottom BI of the housing so that when the shutter forming cylinder Il is raised air can pass out under thevapcrizer.

In the construction shown in Figures 4 and 5 the thermostat Bil and heater 6I are connected into a control circuit, the same as shown in Figure 1, but here the thermostat is designed to operate in they other direction, that is to say to flex upwardly on being heated. This will permit the adjacent end of lever 62 to rise and the remote end El to lower. shaft 6l suitably guided for vertical movement and carrying a shutter member 65 inside the central air distributor 86 and provided with a large central opening 81. The central air distributor has a series of openings 88 larger than the openings i9 contemplated in the construction of Figure 2 and the shutter 85 has small openings 89 corresponding in size with the openings i9. These openings 8B and l! are kept in registry by guides such as indicated at 10. When the shutter 65 is in the lower position as shown in vFigure 5 less air which passes up into the central air distributor is directed down into the vaporizer than when the shutter 65 is up as shown in Figure 4.

From the foregoing it will be apparent that it is possible during low fire or pilot operation to direct into the interior of the vaporizer a much larger proportion of the air supplied by the blower than during high ilre. While automatic electrical operation is generally advantageous it is entirely possible to effect the change manually, especially where the fuel control is anual.

Since it is obvious that. the invention may be embodied in other forms and constructions within the scope of the claims, I wish it to be understood that the particular forms shown are but a few of these forms, and various modifications and changes being possible, I do not otherwise limit myself in any way with respect thereto.

What is claimed is: 1

1. In a liquid fuel burner, in combination, a constant level valve having a metering valve for delivering liquid fuel at a high rate for high dire or at a low rate for pilot operation, a thermostat for operating the metering valve, a remote controlled heater for the thermostat, an annular vaporizer into which the fuel flows by gravity to form an annular pool, a concentric perforated sleeve above the periphery of the vaporizer, a

central air distributor having openings for directing air downwardly into the vaporizer, means for supplying air under positive pressure to the outside of the sleeve and to the inside of the central air distributor, a shutter for controlling' delivering liquid fuel at a high rate for high re -and havingv openings for directing air downwardly into the vaporizer and outwardly below the ilame spreader, means for supplying air under positive pressure to 7the outside of the sleeve and to theinside of the central air distributor, a

The lever supports a vertical shutter for preventing the air from flowing under the flame spreader so that all the air entering the central air distributor must pass downwardly into the vaporizer, a second thermostat for operating the shutter, and a second heater energized concurrently with the first, the second thermostat acting to move the shutter to the open .position in timed relation with the shifting of the metering valve to high fire/position.

3. A burner such as claimed in claim 2, having a second shutter for controlling the flow of air to the outside of the sleeve, the second shutter moving with the first and being open when the first shutter is open.

4. In a liquid fuel burner, in combination, a constant level valve having a metering valve for delivering liquid fuel at a high rate for high lire or at a. low rate for pilot operation, a thermostat for operating the metering valve, a remote controlled heater for the thermostat, an annular vaporizer into which the fuel flows by gravity to form an annular pool, a concentric perforated sleeve above the periphery of the vaporizer, a central air distributor having openings for directing air downwardly into the vaporizer, means for supplying air under positive pressure to the outside of the sleeve and to the inside of the central air distributor, a shutter in the central air distributor and having openings smaller than the openings in the central air distributor for restricting the air flowing from the central air distributor to the vaporizer, a second thermostat for operating the shutter, and a second heater energized concurrently with the first, the second thermostat acting to move the shutter to a position to open the larger openings in timed relation with the shifting of the metering valve to pilot position so as to increase the iow of air to the vaporizer.

5. A liquid fuel burner comprising an annular lio vaporizer having a downwardly and inwardly sloping wall and adapted to form an annular pool of fuel, a central air distributor having holes to delivern air. downwardly onto the inner part of the pool, an outer perforated sleeve to deliver air inwardly across the pool, anair chest about the sleeve and under the vaporizer, means for supplying the air chest with air under pressure for both the sleeve and the central'air distributor, means for controlling the rate of flow of fuel for high fire and for 'low fire respectively, and means operating concurrently with the flow rate control means for increasing the proportion of air which is blown from the centralnair distributor down into the vaporizer when the burner is operating at low nre.

6. A pot type liquid fuel burner having an annular vaporizer, a central air distributor having downwardly opening holes above the inner part ofthe vaporizer and an upwardly extending air passage, a flame spreader carried at the top of the central air distributor and under which air escapes into the flame a substantial distance above the vaporlzer, means for supplying air to the central air distributor from below, a shutter above the openings for closing the air passage leading to' the flame spreader and normally biased-to closed position, a thermostat for operating the shutter to open position, means to Acontrol the ow'of fuel to the vaporizer for high re'and for pilot operation, and means for automatically holding the shutter in the open position when the fuel flow controlling means is adjusted for high fire.

7. A pot type oil burner having a. cylindrical outer shell with an opening in the bottom, a blowing air in through said opening, an. upper ring carried by the shell, a perforated sleeve below and concentric with the ring and inside the shell, an annular vaporizing pot secured below the ring and having a central opening, a central air distributor above the central opening in the pot, a iiamespreader carried by the central air distributor, the central air distributor having air passages for directing a portion of the air forced yup into the central air distributor downwardly into the pot the llame spreader and central air distributor, when assembled, providing other air passages for directing another portion of said air out under the flame spreader, a. shutter carried in the central air distributor for impeding air movement upwardly toward the flame spreader and ydelivering air toward the passages which direct it downwardly into the pot, fuel control means to provide fuel for high fire or for pilot operation, and means operable when the fuel control means is adjusted for high re for automatically opening the shutter.

8; A burner such as claimed in claim 7, having a second normally closed shutter operable by the shutter opening means for regulating the air supply to the shell outside the perforated sleeve and the amount of air which passes through the sleeve.

9. A pot type oil burner having a cylindrical outer shell with an opening in the bottom, a blowposed thereto, the shutter being movable toward and away' from the the openings in the central air distributor so asA to regulate the air passing through the same, fuel control means to provide fuel for high fire or for pilot operation, and means operable when the fuel control means is adjusted for high nre for automatically moving the shutter to the position for restricting air flow through the openings in the central air distributor.

l0. An oil burner having an annular vaporizer provided with a sloping bottom to forman annular pool of varying depth, means to feed oil at a rate to form such a pool and means to reduce the rate so that as the oil is consumed the pool recedes inwardly, a blower, an air chest receiving air from the blower, an outer sleeve above the periphery of the vaporizer and having holes for directing air inwardly above the vaporizer, a central air distributor having holes for directing air downwardly into the deepest part of the vaporizer, said holes communicating with the air chest and being of such sizes as to deliver air in predetermined proportions for operating the burner at high fire, movable means to redistribute the air. ow so that a greater portion of the air may be sent through the holes in the central air distributor,- and thermostatically operated means acting concurrently with the fuel now rate controlling means for actuating the movable meansto redistribute theV air when the rate is reduced.

1l. The method of burning liquid fuel which comprises supplyingzan annular vaporizer having a sloping bottom with liquid fuel at a high rate to form a pool therein for high fire operation and at a. low rate for a pilot flame, blowing air in xed proportions against the deeper and the outer pe'- ripherai portions o! the pool for high nre, and concurrently with the change of rate of fuel flow to the low rate increasing the proportion of air blown toward the deeper part of the pool to increase the air supplied to the narrowing pool surface as the fuel is being consumed.

12. The improvement in annular pot type burners having a central air distributor carried on top of the inner periphery of the pot, the central air distributor having an outer cylindrical wall of larger diameter than the inner periphery of the pot and openings for delivering air downwardly into the pot, s, name spreader carried by and spaced from the top oi' the central air distributor. and a baille supported inside the central air distributor above the openings and having an opening smaller than the interior opening in the central air distributor to impede air movement up. 

